Assembly of highly efficient overall CO₂ + H₂O electrolysis cell with the matchup of CO₂ reduction and water oxidation catalyst

The exploitation of highly active and stable catalysts for reduction of CO2 and water oxidation is one of the approaches to facilitate scalable and sustainable CO2 reduction potentially at the industrial scale. Herein, a feasible strategy to rationally build an overall CO2 + H2O electrocatalytic reaction device is the preparation and matchup of a high-performance CO2 reduction catalyst and low-cost and highly active oxygen anode catalyst. A heterostructured nanosheet, gamma-NiOOH/NiCO3/Ni(HCOO)(2), exhibited superior catalytic activity in the oxygen evolution reaction, and was integrated with CoPc/Fe-N-C to build an overall CO2 + H2O cell with a current density of 10 mA cm(-2) at a very low cell voltage of 1.97 V, and the faradaic deficiency of CO2 to CO was maintained at greater than 90% at 1.9 V.